As a musician were always told to play on tune but how does one actually learn to recognize those subtle differences in pitch to know if we are flat or sharp? It would be nice if there is an app to help teach this. This app is it! Highly recommended. Great to "play" a few minutes a day. I expect my scores to improve over time. Some future recommendations if possible - allow the ability to repeat incorrect answers so people can learn from mistakes. Other sounds would be nicer if possible (brass, piano etc.) Well done